A new agreement forcing countries to reduce greenhouse gas emissions is crucial

Here we go again. This weekend, as in every year for the past 18, thousands of negotiators, lobbyists, activists, journalists and assorted hangers-on are converging on a cavernous conference centre to haggle over one of the most complex, frustrating and urgent tasks of our times – the prevention of catastrophic climate change.

This time, the travelling circus is pitching up in Doha, in Qatar, which emits the most carbon dioxide per person in the world, nearly three times the US level. As always, it will have its fair share of clowns, big beasts (with a few would-be tamers), and people trying to ride two horses at once. And no doubt, as usual, it will end with a tense all-night highwire act, in which everything almost comes crashing to the ground.

If it tumbles off the tightrope this time, the world will be left without any international provisions to control emissions: those under the Kyoto Protocol expire on December 31. But the betting must be that it will again shakily survive.

Not that the negotiations have so far had any great effect. Total annual greenhouse gas emissions have increased by about a third over the past decade, even as the delegates have deliberated, and carbon dioxide concentrations in the atmosphere are now higher than at any time in the past 15 million years.

Last month, the US government has just reported, was the 332nd in succession in which the global temperature was above the average for the 20th century: though individual areas have sometimes suffered cold spells, the last below-average month worldwide was February 1985. And the effects are increasingly showing. The European Environment Agency this week published a 300-page report detailing the impact of global warming on the continent, from crops to coasts, floods to forests – and earlier this year the giant Climate Vulnerability Monitor report concluded that it was already costing about 1 per cent of global GDP and, together with the carbon-based economy, causing five million deaths a year, mainly in poor countries.

Authoritative alarms have been sounding almost daily while the Government has been grappling with its deep divisions over clean electricity generation. Last week, the International Energy Agency warned that the world was about to “lock itself into an insecure, inefficient, and high-carbon energy system”. On Monday, the un-alarmist World Bank reported that “devastating” climate change threatened to make the world “dramatically different”. And on Wednesday, a report by the United Nations Environment Programme showed that the pledges so far made by countries on cutting emissions fall far short of what will be needed to bring global warming under control.

So no pressure, then. The delegates’ first task will be to ensure the survival of the Kyoto Protocol, with countries that agree to be bound by it signing up to new reduction targets. This is of enormous symbolic significance to developing countries; the negotiations are likely to collapse without it. But its practical impact is far smaller. Only Europe, Australia, Switzerland and Norway are likely to sign up: the really big polluting countries – China, the United States and India – are unaffected.

The big task, therefore, is to make progress on a commitment made at the last climate summit, in Durban last year, to reach a new agreement “with legal force” by 2015, binding all countries to control emissions. This, in itself, was a breakthrough, and there are some reasons for cautious optimism that progress will continue.

Many of the obstacles to progress in the past are diminishing. The United States – through regulation and using shale gas – is likely to hit its target for reducing emissions by 17 per cent by 2020, and President Obama has started to talk about acting on climate change, for the first time in years, after his election and Superstorm Sandy.

China – the main problem at the 2009 Copenhagen summit – is starting its own emissions trading scheme to control carbon releases, and its new leadership is expected to give a higher priority to the environment. And Saudi Arabia, long the strongest opponent of change, is now investing heavily in solar power.

But even a strong new agreement, if it happens, would not be due to take effect until 2020, by which time emissions will already have to be decreasing if dangerous climate change is to be avoided. So delegates will also discuss what measures might be taken in the meantime.

It all adds up to a big test for Ed Davey, the Climate Secretary, whose predecessor Chris Huhne was central to brokering agreements at the past two summits. Fresh from fighting George Osborne to a score draw over energy policy, he now needs to cultivate a new skill – as a circus ringmaster.

MINISTERS DIG A DEEPER HOLE FOR THEMSELVES ON PLANNING

It doesn’t give up easily, does it? Frustrated in its attempt to turn the planning system into a developers’ charter, argued out of weakening protection for the green belt, the Government is now limiting citizens’ ability to have decisions judicially reviewed.

Launching the plan this week, the Prime Minister made much of a recent increase in reviews. But this was in the areas of asylum and immigration – the number of other cases has fallen since 2006. He also said he’d cut the time limit for applications: but lawyers point out that, unusually, cases must already be brought “promptly”.

Anyway, most judicial reviews are not about the merits of a government decision, but whether it was arrived at fairly and lawfully. Do ministers want to aid unfairness and lawbreaking?

The move also contradicts the Tories’ promise to give more power to local people. Before the election, they pledged to end the injustice whereby a developer can appeal a decision not to give planning permission, but local people cannot do so when a development is approved.

Now, not only has the Government failed to do this, but it plans to limit one of the few recourses left to residents. Before the election it warned that such local alienation turned people “against the notion of development itself”. Time for some homework.

OYSTERS, NOT TURKEY, FOR THE ECO-FRIENDLY THANKSGIVING

You’ve heard of champagne socialists, but how about this? US environmentalists are being urged to scoff down the ultimate green food. But not alfalfa, tofu or even nut roast: oysters.

Grist, a Seattle-based green web magazine, makes the bivalves its choice for Thanksgiving dinner, dismissing turkeys – an estimated 45 million of which were gobbled up by Americans on Thursday – as “the hands-down worst option”, having endured lives “right up there with The Silence of the Lambs”.

Oyster farming has a “very small environmental impact” as it “essentially involves plopping the molluscs into the sea and letting them go to maturity” without escaping to devastate native ecosystems.

Elsewhere, a vegan who appreciates fine oysters insists: “When it comes to ethical eating, they are almost indistinguishable from plants.”

The gourmet greenies even brandish a “Best Choice” recommendation from the famed Monterey Bay Aquarium, which says farming the filter-feeders cleans coastal waters.

For those who can’t stomach the shellfish, Grist produced a Thanksgiving recipe for Veggieducken – squash, encasing yams, wrapped round leeks – but called it “a time-consuming pain in the ass”.